In order to connect a single or two high-power photovoltaic modules into a single-phase photovoltaic grid-connected system

a low-voltage stress interleaved high-gain interface converter is presented. The proposed converter is obtained by constructing the inverse Boost circuit and connecting it differentially with its mirror topology. Under the conventional symmetrical control (i.e. the driving signals of two switches have a phase difference of 180° and their duty cycles are equal to d)

the proposed converter has the following advantages: the voltage gain is (3−d) times that of conventional Boost converters; the voltage stresses of all power components are equal and less than half of the output voltage Uo

and decreases with the increase of the input voltage Uin; the input inductor currents can be automatically balanced within the full duty cycle range without the the help of current sensors

and are less than half of the input current Iin; since the components in the two-phase circuit are the same

they can be used interchangeably

being suitable for mass production. In addition

the converter has a continuous input current with a low ripple rate and a constant input/output voltage difference. The working principle and steady-state characteristics of the proposed converter in continuous conduction mode are analyzed in detail

and the design method for power stage parameters is given. The correctness of the theoretical analysis is verified by a 500 W/50 kHz prototype experiment. The results show that the minimum efficiency of the system is 96.9%

and the maximum efficiency is 98.8%.